The present disclosure relates to a fixing device to fix a toner image on a sheet, an image forming apparatus including the fixing device and a holding member forming method.
In the fixing device, between a heating member, such as a fixing belt or a fixing roller, and a pressing member, such as a pressing roller, a pressing area is formed. When a sheet on which a toner image is transferred is passed through the pressing area, the toner image is heated and pressed to be fixed on the sheet. In a case where the fixing belt is employed as the heating member, a holding member configured to hold the fixing belt to the pressing member is provided.
The fixing device is sometimes provided with a nip forming member, as the holding member, including a base plate and a sliding sheet wrapped around the base plate. The base plate has projections on the face opposite to a nip area (the pressing area). The sliding sheet has openings into which the projections are fitted. The sliding sheet is wrapped around the base plate with the projections fitted into the openings.
However, in the above fixing device, in order to make it easier to fit the projections of the base plate into the openings of the sliding sheet, the sliding sheet has a length longer than a length where the sliding sheet is wrapped around an outer circumference of the base plate closely. Thereby, in a state where the projections are fitted into the openings, the sliding sheet is wrapped around the base plate with a loosed portion. When the fixing belt is rotated in the state where the sliding sheet is wrapped around the base plate with the loosed portion, the sliding sheet is pulled downstream, and the loosed portion is expanded downstream. Then, the expanded loosed portion is slid to the fixing belt, and rotation load of the fixing belt becomes large. As a result, a sheet jam easily occurs owing to rotation failure of the fixing belt.